Seroprevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Following the Largest Initial Epidemic Wave in the United States: Findings From New York City, 13 May to 21 July 2020

Abstract Background New York City (NYC) was the US epicenter of the spring 2020 coronavirus disease 2019 (COVID-19) pandemic. We present the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and correlates of seropositivity immediately after the first wave. Methods From a serosurvey of adult NYC residents (13 May to 21 July 2020), we calculated the prevalence of SARS-CoV-2 antibodies stratified by participant demographics, symptom history, health status, and employment industry. We used multivariable regression models to assess associations between participant characteristics and seropositivity. Results The seroprevalence among 45 367 participants was 23.6% (95% confidence interval, 23.2%–24.0%). High seroprevalence (>30%) was observed among black and Hispanic individuals, people from high poverty neighborhoods, and people in healthcare or essential worker industry sectors. COVID-19 symptom history was associated with seropositivity (adjusted relative risk, 2.76; 95% confidence interval, 2.65–2.88). Other risk factors included sex, age, race/ethnicity, residential area, employment sector, working outside the home, contact with a COVID-19 case, obesity, and increasing numbers of household members. Conclusions Based on a large serosurvey in a single US jurisdiction, we estimate that just under one-quarter of NYC adults were infected in the first few months of the COVID-19 epidemic. Given disparities in infection risk, effective interventions for at-risk groups are needed during ongoing transmission. A large serosurvey following the first wave of the coronavirus disease 2019 epidemic in New York City found that just under one-quarter of adults were infected. Observed disparities in infection risk highlight needs for ongoing, effective interventions in at-risk groups.